Relay



Dec. 23, 1941. c. P. CLARE ETAL 2,267,191

RELAY Filed: Dec 26, 1939 Carl f? C'Zczr'e and 3!: G76 Zl/einreicfPatented oecsza, 1941 RELAY Carl P. Clare, Park Ridge, and GeorgeWeinreich, Chicago, Ill., assignors to 0. P. Clare & Co., Chicago, 111.,a corporation of Illinois Application December 26, 1939, Serial No.310,960

4 Claims.

The present invention relates to relays for .controllmg various electriccircuits. It is more particularly concerned with the actuation of the'relay springs which carry the movable contacts and the means by which aplurality of springs are operated from a single actuating arm. In relaysof the type to which the present invention applies, it is customary toprovide the several spring arms with spacers of insulating material andto provide the actuating arm with an insulating member that engages thefirst spring. The insulating members transmit the movement of theactuating arm to the first spring and from there to each succeedingspring. It is evident that the accuracy with which the insulatingmembers are manufactured and maintained is very important in thecontinued operation of the relay. A small amount of wear on each of theinsulating members will result in an accumulative error which, in ashort time, will make the relay inoperative. It is also evident thatthese insulating members must be free from objectionable swelling orshrinkage due to changes in humidity or temperature of the surroundingatmosphere.

The present invention contemplates the production of a novel insulatingmember for interposition between the actuating arm of the relay and theadjacent springs, and between the several springs which are tobe movedby the actuating arm. Heretofore, various types of insulating membershave been employed, but apparently they have not been designed with afull understanding of the problem involved. Hard rubber insulatingmembers have been utilized, but they have the objection that they wearrapidly and the dust on the relay contacts seriously impairs theconductivity, often times resulting in failures. The hard rubberinsulating members also have the difiiculty that they are not capable ofwithstanding a very high temperature without softening.

We have considered the matter of fiber insulating members, but suchmaterial has been found to be too susceptible to atmospheric conditionsfor the accuracy desired. Furthermore, the fiber material isstructurally weak and will often break in riveting the insulatingmembers to the spring.

We have found that a certain construction of insulating member utilizingsynthetic resin to be very satisfactory for our purpose. It is necessaryto construct the insulating member in a particular fashion in order toobtain the desired results. The construction of such insulating memberand its embodiment in the relay constitute the novel features of thepresent invention.

The features and advantages of the present invention will appear morefully as the description proceeds, reference being had to theaccompanying drawing wherein a preferred form of the invention is shown.It is to be understood, however, that the drawing and description areillustrative only, and are not to be taken as limiting the inventionexcept insofar as it is limited by the claims.

In the drawing:

Fig. 1 is an assembly view of a relay to which the present invention isapplied;

Fig. 2 is an enlarged sectional view taken on the line 22 of Fig. 1 andillustrating the mounting of the insulating members on the actuating armof the relay and on the spring;

Fig. 3 is an enlarged sectional view taken on the line 33 of Fig. 2.

Referring now in detail to the drawing, the coil portion of the relay isindicated by the numeral Ill. The armature of the relay is indicated atII. This armature carries an arm I2 and the armature is pivoted by meansof a pivot pin I3. The stationary contacts of the relay are indicated atI and I5, the contacts ll being the back contacts, while the frontcontacts are the contacts I5 that are made when the relay coil isenergized. The movable spring contacts of the relay are indicated at I5,two contacts of this type being shown. It is evident, of course, thatthe contacts I6 may include one or several spring contacts, dependingupon the particular purpose for which the relay is designed.

Actuation of the spring contacts I6 is by means of the arm I2. This armcarries an insulating member I! to engage the first spring. The secondspring has riveted thereto an insulating member I8. Succeeding springswould also have insulating members similar to I8 thereon. The rivet I9secures the insulating member I8 to the second spring Hi.

It will be appreciated that in transmitting the movement of the arm I2to the first spring contact and through this spring contact to thesucceeding spring contact of the relay, the insulating members I1 and I8are continually subjected to wear at their free ends. Furthermore, inmounting the insulating member I1 upon the arm l2 it is necessary tosecure it, and in order to do so, the most desirable manner of securingis by a drive fit by which the arm is secured in a recess provided inthe insulating member IT. We have found normal construction of rods ofsynthetic resin material and fibers to be totally impractical for thispurpose, the reason being that a cleavage of the insulating memberresults from the interior pressure. The insulating member l8 encountersmuch the same difflculty in securing it to the spring contact by meansof the rivet l9. We have endeavored to use ordinary commercial forms ofrods made from synthetic resin material such as Bakelite. However, suchmaterials develop cleavage lines where they have little or no strength,and the destruction of the insulating members is too frequent forpractical use. On the other hand, the synthetic resin materials do havevery fine wearing qualities, particularly where the constructionincludes an impregnated paper or fabric as a part of the finished rod.

In order to obtain the desired characteristics, we have found itnecessary to construct our insulating materials in the following manner.We first take ordinary sheet material of synthetic resin which is madefrom a plurality of layers of paper impregnated with the resin andpressed together. From this material, rods 2| are out, the rods being ofvery small diameter in the neighborhood of less than one-eighth inch.Cleavage lines of course appear in these rods parallel to thelaminations. In order to overcome this weakness, we then wrap the rodswith paper which has passed through the synthetic resin compound so asto build up a coil 20 of resin impregnated paper about the rod which iscut from the sheet. The rod is then cured with the coiled impregnatedpaper about it by placing it in a mold and subjecting it to thenecessary heat and pressure. From the resulting rod, we cut the lengthsthat are used for the insulating members I! and I8.

It will be noted that the maximum strength of these rods lies in therolled portion 20 around the central rod 2i, and it is the central rodportion that is drilled out in order to receive the tip of the arm H orthe rivet I 9. There is no radial line of cleavage in the rod. Thus thefull strength and advantage of the impregnated paper is available toprevent cracking of the insulating member.

It has been proposed to roll the rods initially without a center rod andthus avoid the apparently expensive process of originally forming Theinsulating members constructed in the manner hereinbefore described havethe advantages oi sufiicient tensile strength to avoid breakage whenfitting them on the arms and the rivets. They also have the advantage ofwearing very slightly where they contact the surfaces of the springcontacts. They take a very high polish and when the surface of thespring is also polished, a very long life results. The temperaturecharacteristic is also very good. With the ordinary Bake1ite" material,there is no softening at temperatures which the relays will normallystand. Since the material is inherently a water repellent and has a lowtemperature coemcient of expansion, atmospheric conditions do notseriously affect the operation of the relay by changing the lengths ofthe insulating members.

From the foregoing description it is believed that the construction andadvantages of our invention will be readily apparent to those skilled inthis art. Having thus described our invention. what we claim as new anddesire to secure by Letters Patent is:

1. A movement transferring spacer for relay springs and the likecomprising an inner rod section of phenolic resin impregnated sheets ofpaper having planar lines of cleavage, and a shell section of phenolicresin impregnated paper coiled about said rod section and intimatelyunited therewith.

2. A movement transferring spacer for relay springs and the like,comprising an inner rod of insulating material, said rod having mountingmeans therein, and a peripheral shell encircling said rod, saidperipheral shell being composed of a plurality of layers of fibroussheet material impregnated with an insulating composition and fittingtightlyabout the rod.

3. A movement transferring spacer for relay springs and the like,comprising a rod section of insulating material having a recessextending into it from one end thereof, said rod being provided with anaperture leading from said recess to the other end thereof to receive afastener, a fastener mounted in the aperture, and a peripheral shell onsaid rod composed of circumferential layers of fibrous materialimpregnated with an insulating composition and free of radial cleavagelines.

4. A movement transferring spacer of the character described, comprisingan inner rod of insulating material having a recess therein extendinginwardly from one end thereof, and a peripheral shell encircling saidrod, said shell being composed of compressed layers of a fibrous sheetimpregnated with an insulating composition, the layers encircling therod.

. CARL P. CLARE.

GEORGE WEINREICH.

